From The Enigma
NPL Magazine
April, 2019
EARL E. BYRD

The four words that complete this flat contain only the letters C, E, N, O, R - repeated if necessary - with one word using only four of the letters

The old lady sat where the walls
   chanced to meet,
And she sang in a voice that was
   gentle and sweet.
That _ _ _ _ _ in the _ _ _ _ _ _
   Was a _ _ _ _ _ _ _ at the _ _ _ _,
So, enchanted, I lingered
   To listen some more

Answer:

That CRONE in the CORNER
   Was a CROONER at the CORE